Blinds of early days were controlled by blind cords where a switching controller was installed at one end of the track located on top of a blind. A bead chain or a blind cord was hanging down from the switching controller to lift or lower the blind by pulling the bead chain. However, accidents of strangling small children by the bead chains have been occurred, therefore, blinds with bead chains have been forbidden in many countries. Hence, cordless blinds become household necessities. Even though there are many different designs of cordless blinds, their switching operation is not as convenient as blinds with cords.
The conventional cordless blinds hide the blind cords inside the blind with an exposed spool to collect the blind cords and are operated by an extra installed stopping control device to fully open/close the cordless blinds. However, the cordless blinds can not be stopped at any position according to user needs. Furthermore, the stopping control device of a cordless blind is customized and is designed and manufactured according to the weight and dimension of a cordless blind. If a stopping control device does not match with the dimension and weight of a cordless blind, the cordless blind either suddenly drops to hurt someone below or completely and automatically lifts without fully close function. Moreover, the exposed spool is easily contaminated when used in years where the blind cords can not easily be rolled up. It is also time-consuming to install cordless blinds with exposed spools.